Marks the period during which DNA synthesis or replication takes place. During this time, the amount of DNA per cell doubles, but number of chromosomes remain same.

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During this time, the amount of DNA per cell doubles, but a number of chromosomes remain same.

Cell cycle completes in two steps- Interphase and M-phase. Interphase is completed in three successive stages G1-phase (post-mitotic phase), S-phase (synthetic phase) and G2-phase (pre-mitotic or post-synthetic phase). In the given figure, D is representing the S-phase (synthetic phase) of cell cycle.